It’s so on.  Arlen Specter and Joe Sestak began their primary campaigns early today for the Democratic nomination for the Senate, not over policy, but over which of them had more right to the (D) next to their names:

Specter called Sestak a “flagrant hypocrite” for challenging Specter’s Democratic credentials. Specter switched political parties in April after 29 years as a Republican when it became clear he was headed for an epic GOP primary battle.

Specter said Sestak, a retired Navy vice admiral, didn’t register as a Democrat until 2006, when he ran for Congress.

“His lame excuse for avoiding party affiliation, because he was in the service, is undercut by his documented disinterest in the political process,” Specter said, noting that Delaware County records showed that Sestak voted in only 12 of 35 general elections from 1971 to 2005. He also pointed out that he did not vote in President Clinton’s 1996 election despite working in the White House at the time.

Uh, yeah, sure.  Sestak has only been a Democrat for three years, but Specter hasn’t yet been one for three months.  Specter can push back against Sestak’s criticism by talking about the issues, but if he’s looking to run on the notion that he’s a more loyal Democrat than Sestak, Specter will lose, and lose big.

Sestak punched back:

“Like Colin Powell (who was registered as an Independent while he served), I believe that military officers should be nonpartisan.”

Sestak said he was proud to be an independent during his 35 years in the Navy and to register as a Democrat as soon as he retired from active duty.

“Let’s be clear: I voted for Bill Clinton, Al Gore, John Kerry, and Barack Obama while Arlen Specter was voting for George Bush and Bob Dole and John McCain,” he said. “My question to Arlen Specter is this: Do you regret voting for George Bush and John McCain? Why should Democrats support someone like you who actively campaigned — as recently as last year — for politicians with values like George W. Bush?”

I’m not sure I’d push the Bush-hatred much farther, if I was Sestak.  At the rate independents are bailing on Barack Obama, Bush might start looking pretty good in comparison, especially in Pennsylvania, where Obama threatens to create an economic depression in coal country.  Otherwise, he makes a good point.  We should be encouraging non-partisanship in our military leadership, not declarations of loyalty to political parties.  And how exactly does Arlen explain campaigning for Republicans until one of them threatened to end his lifetime job in DC?

Sestak wins this round, but I’m happy to say it’s not a knockout.  I’m hoping this one will go the distance, just like in Rocky, with both fighters so bloodied that Pat Toomey has a walkover in 2010.  Pass the popcorn and enjoy.